JPS6363951A - Power source unit for ultraviolet flaw detection - Google Patents

Abstract

PURPOSE:To obtain a small and light weight power source unit which reduces variations in the radiation of ultraviolet rays regardless of changes in the voltage while increasing the amount of ultraviolet rays, by converting a commercial AC power source to a higher frequency to be supplied to a discharge lamp lighting circuit and an incandescent lamp lighting circuit. CONSTITUTION:With a circuit 3, a commercial AC 1 undergoes a full-wave rectification 10 to be smoothed 11 and applied to a primary winding 15a of a transformer 15 through transistors 13 and 14 PP connected to a constant current inductance 12. A base is wound with a feedback winding 15c and a high frequency voltage is generated in a secondary winding to light a discharge lamp 5. Here, the amount of ultraviolet rays increases by about 8% while the rate of change in the radiation is reduced to one half with respect to the variation in the source voltage. With a circuit 4, a base current flows through resistances 19 and 20 by a DC voltage smoothed and an AC signal is applied between the base and emitter of a transistor 21 synchronizing the frequency generated in a control winding 22 of the transformer 15 to light an incandescent lamp 6 synchronizing the discharge lamp 5. This eliminates the need for a transformer with a commercial frequency, thereby enabling a smaller size and a lighter weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device for ultraviolet flaw detection that detects defects such as scratches on a sample by using ultraviolet light emitted by a discharge lamp.

[Conventional technology]

Metal workpieces such as aircraft fuselages and railway vehicle axles require high reliability. However, defects such as scratches due to metal fatigue may occur in such metal workpieces. In order to detect such defects, ultraviolet flaw detection methods such as fluorescent magnetic particle flaw detection and fluorescent penetrant flaw detection have been widely used.

FIG. 4 is a circuit diagram of a conventional power supply device for ultraviolet flaw detection.

In FIG. 4, 51 is a commercial AC power supply, 52 is a power supply circuit consisting of a discharge lamp lighting circuit 53 and an incandescent lamp lighting circuit 54, 55 is a discharge lamp, 56 is an incandescent lamp, and 57 is a switch. Further, the discharge lamp lighting circuit 53 includes a leakage transformer 53a, and the incandescent lamp lighting circuit 54 includes a step-down transformer 54a.

Although not shown, the discharge lamp 55 is equipped with an optical filter to cut visible light and to emit visible light at a specific wavelength (in many cases,
It is designed to emit only ultraviolet rays (365 nm).

The operation of the conventional power supply device for ultraviolet flaw detection with the above configuration will be explained. First, a flaw detection agent containing a phosphor is applied to a sample in advance. Next, the sample is irradiated with ultraviolet rays emitted by the discharge lamp 55. If a sample has a defect such as a flaw due to metal fatigue or the like, the flaw detection agent attached to the defect portion receives ultraviolet light and emits light, making it possible to easily detect the defect portion.

[Problem that the invention seeks to solve]

By the way, ultraviolet rays are used for deep damage 6! In order to detect defects in a sample using the However, the conventional IIT source device for ultraviolet flaw detection employs a magnetic circuit system using a leaky transformer 53a having a silicon steel plate or a magnetic/magnetic wire, and therefore has the disadvantage of being large and heavy.

In addition, when inspecting a sample using a conventional ultraviolet flaw detection power supply, if the voltage of the commercial text [1fi51 fluctuates, the amount of ultraviolet rays emitted from the discharge lamp 55 also fluctuates, and the voltage of the electric While the fluctuation rate is 10%, the fluctuation rate of the amount of ultraviolet rays is approximately 20%. For this reason, the conventional apparatus has the disadvantage that when the power supply voltage fluctuates, the detection level of defects in the sample fluctuates, making it difficult to accurately detect the state of defects. FIG. 5 is a diagram showing a constant power type discharge lamp lighting circuit that eliminates this drawback. In FIG. 5, 61 is a choke coil, 62 is a saturable transformer, and 63 is a capacitor. The discharge lamp lighting circuit shown in FIG. 5 can always supply constant power to the discharge lamp 55, which is the load, even if there is a fluctuation in the power supply voltage.

However, since the 1IAIT device for ultraviolet flaw detection having the discharge lamp lighting circuit shown in FIG. 5 uses the saturable transformer 62, the amount of silicon W4 plate and magnet wire used is Increased power supply for
This method has the disadvantage that it is larger and heavier than the device shown in FIG. 4.

Furthermore, the power supply device for ultraviolet flaw detection can be used for inspecting samples.
Since it may be used in a dark place, it is necessary to illuminate defects such as scratches on the sample so that the inspector can easily see them with the naked eye. For this reason, the device includes five incandescent lamps for illumination.
6 is provided.

These incandescent lamps usually have a power consumption of about IOW, but due to luminous efficiency, commercial AC T:
Since it is often necessary to use a rated voltage lower than the voltage of the i-source 51, the incandescent lamp lighting circuit 54 requires a step-down transformer 54a. Like the saturable transformer 62, the step-down transformer 54a is made of a silicon steel plate or a magnet wire, and thus contributes to the increase in size and weight of the ultraviolet flaw detection power supply device.

The present invention has been made based on the above circumstances, and provides a power source for ultraviolet flaw detection that is small, lightweight, and easy to carry, and in which the amount of ultraviolet radiation emitted by a discharge lamp does not fluctuate even if the power supply voltage fluctuates. The purpose is to provide equipment.

(Means for Solving the Problems) To achieve the above object, the present invention includes a commercial AC power supply, a discharge lamp that emits ultraviolet rays, and a discharge lamp that lights the discharge lamp using the commercial AC IS. The lamp includes a lighting circuit, an incandescent lamp for illumination, and an incandescent lamp lighting circuit that lights the incandescent lamp using the commercial AC power source, and irradiates the sample with ultraviolet rays emitted by the discharge lamp to remove scratches on the sample. In the ultraviolet flaw detection power supply device for detecting defects in the discharge lamp and the incandescent lamp, the discharge lamp lighting circuit and the incandescent lamp lighting circuit convert the commercial AC power source into an AC power source with a frequency higher than the commercial frequency, and then convert the commercial AC power source into an AC power source with a frequency higher than the commercial frequency. It is configured to supply incandescent lamps.

[Effect]

With the above-described configuration, the present invention can light up the discharge lamp and the incandescent lamp using AC fL power having a frequency higher than the commercial frequency, thereby making it possible to reduce the size and weight of the device. In addition, by lighting discharge lamps using AC power with a frequency higher than the commercial frequency, it is possible to reduce fluctuations in the amount of ultraviolet radiation emitted by the discharge lamp even if there are fluctuations in the power supply voltage. can increase the amount of ultraviolet light emitted by

〔Example〕

A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a circuit diagram of a power supply device for ultraviolet flaw detection, which is a first embodiment of the present invention. In FIG. 1, 1 is a commercial AC power source, 2 is a power supply circuit, 3 is a discharge lamp lighting circuit, 4 is an incandescent lamp lighting circuit, 5 is a discharge lamp, 6 is an incandescent lamp, and 7 is a switch. Further, the discharge lamp lighting circuit 3 includes a rectifier circuit 10,
A smoothing circuit 11, a constant current inductor 12, oscillation transistors 13 and 14, and a high frequency transformer 1 for a discharge lamp.
5, resistors 16 and 17, and a capacitor 18.

The incandescent lamp lighting circuit 4 includes a transistor 21, an incandescent lamp transformer 23, and resistors 19 and 20. Furthermore, 15a
is a primary winding of the high frequency transformer 15, 15b is a secondary winding of the high frequency transformer 15, 15C is a feedback winding of the high frequency transformer 15, and 22 is a control S line.

Next, the operation of the first embodiment device configured as described above will be explained. First, the discharge lamp lighting circuit 3 will be explained. The alternating current of the commercial alternating current source 1 is full-wave rectified by the rectifier circuit 10 and becomes a pulsating wave. After this pulsating current wave is smoothed by the smoothing circuit 11 and converted into a DC output, it is sent to the primary winding 15a of the high frequency transformer 15 via the oscillating transistors 13 and 14 connected in push-pull to the constant current inductor 12. applied. In addition, the transistor 13.1
Since the feedback winding 15C is connected to the base of 4,
The transistors 13 and 14 alternately repeat a conductive state and a non-conductive state, and as a result, a high frequency voltage is generated in the secondary winding 15b of the high frequency transformer 15, and the discharge lamp 5 is lit.

When the discharge lamp 5 of the device of this embodiment is turned on and the amount of ultraviolet light with a wavelength of 365 nm emitted by the discharge lamp 5 is measured, it is found that the amount of ultraviolet light emitted by the discharge lamp of a device operating at the conventional commercial power frequency is as follows. The amount of ultraviolet radiation of this example device is approximately 8%
To increase. Although this measurement result was obtained for a 100 W discharge lamp, similar measurement results were obtained for discharge lamps with other rated power, in which the amount of ultraviolet radiation was increased compared to the conventional device. However, this measurement result was obtained when discharge lamps with the same lamp power were lit using both devices.

In addition, the discharge lamp 5 is lit at the rated voltage, and the power supply voltage is ±10
The rate of change in the amount of ultraviolet radiation when the amount of ultraviolet radiation varies by % is ±20% as described above in the conventional device, whereas the rate of change in the device of this embodiment is ±10%. That is, by using the high frequency power supplied to the discharge lamp 5, the device of this embodiment can reduce the fluctuation rate of the amount of ultraviolet radiation when the electric voltage changes to about half the fluctuation rate of the conventional device. Can be done.

Furthermore, if the frequency supplied to the discharge lamp 5 of this embodiment is set to be higher than the audible frequency, the noise of the device can be reduced.

The discharge lamp lighting circuit 3 has been explained above.Next, we will explain the incandescent lamp lighting circuit that illuminates the defective part of the sample so that defects such as scratches on the sample can be easily confirmed with the naked eye even in a dark place. do. Transistor 21 of incandescent lamp lighting circuit 4
, a rectifier circuit 10 and a smoothing circuit 11 of the discharge lamp lighting circuit 3 are included.
By the DC voltage rectified and smoothed by
9 and 20, and the control winding provided in the high frequency transformer 15! By applying an AC signal synchronized with the operating frequency of the discharge lamp 5 generated at the transistor 22 between the base and emitter of the transistor 21, the transistor 21
repeats a conductive state and a non-conductive state in synchronization with the operating frequency of the discharge lamp 5. As a result, a voltage synchronized with the operating frequency of the discharge lamp 5 is generated on the secondary side of the transformer 23, and this voltage Incandescent lamp 6 lights up. By lighting the incandescent lamp 6 at a high frequency in this manner, a step-down transformer for the commercial frequency, which is required when lighting at a commercial frequency, becomes unnecessary. Therefore, in this respect as well, the device of this embodiment is smaller and lighter than conventional devices.

As described above, according to the device of the present embodiment, by lighting the discharge lamp with AC power at a frequency higher than the commercial frequency, more radiation is emitted from the discharge lamp than when lighting with commercial frequency power. It is possible to increase the amount of ultraviolet rays, and also to reduce fluctuations in the amount of ultraviolet radiation with respect to fluctuations in the power supply voltage.

Furthermore, according to the device of this embodiment, it is possible to light a discharge lamp or an incandescent lamp without using a commercial frequency transformer, so the weight of the device can be reduced to about 1/8 of that of conventional devices. In addition to being able to rotate, power loss can be significantly reduced.

FIG. 2 is a circuit diagram of a power supply device for ultraviolet flaw detection, which is a second embodiment of the present invention. In the second article, the difference between the second embodiment device and the first embodiment device is the incandescent lamp lighting circuit 4.
is constituted by an incandescent lamp layer winding L124 wound around the high frequency transformer 15 of the discharge lamp lighting circuit 3. As a result, the incandescent lamp 6 is lit at the same frequency as the discharge lamp 5. Other functions and effects are similar to those of the first embodiment.

FIG. 3 is a circuit diagram of a source device for ultraviolet flaw detection, which is a third embodiment of the present invention. In FIG. 3, the device of the third embodiment differs from the device of the first embodiment in that the base current of the transistor 21 of the incandescent lamp lighting circuit 4 is rectified and smoothed by the discharge lamp lighting circuit 3 to produce a DC voltage. is passed through the resistor 28, and the AC signal generated at the third winding 25 wound around the transformer 23 is passed through the transistor 21 through the resistor 29.
The point is that it is added between the base and emitter of.

Thereby, the incandescent lamp 6 can be lit at a frequency different from the frequency of the discharge lamp 5. Other functions and effects are similar to those of the first embodiment.

Note that the present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiments, an incandescent lamp is lit with alternating current, but this also applies if it is lit with direct current obtained by rectifying alternating current. good.

〔Effect of the invention〕

As explained above, according to the present invention, since a commercial frequency transformer is not used, the present invention is small, lightweight, and easy to carry, and even if the mam pressure fluctuates, the amount of ultraviolet radiation emitted by the discharge lamp can be reduced. Since there is little variation, it is possible to provide a power supply device for ultraviolet flaw detection that can reliably detect defects such as scratches on a sample.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a power supply device for ultraviolet flaw detection which is a first embodiment of the present invention, FIG. 2 is a circuit diagram of a power supply device for ultraviolet flaw detection which is a second embodiment of the present invention, and FIG. FIG. 4 is a circuit diagram of a conventional power supply device for ultraviolet flaw detection, and FIG. 5 is a diagram showing a conventional constant power discharge lamp lighting circuit. 1... Commercial AC power supply, 2... Power supply circuit, 3... Discharge lamp lighting circuit, 41.・Incandescent lamp lighting circuit, 56. . Discharge lamp, 6.0. Incandescent light, 7... switch, 10...
- Rectifier circuit, 11... Smoothing circuit, 12... Constant current inductor, 13.14... Transistor, 15.
・・High frequency transformer, 16・17・19・20・28・
29...Resistor, 18...Capacitor, 21...
Transistor, 22... Control winding, 23... Transformer, 24... SvA for incandescent lamp, 25... Third winding. Applicant: i-Writing System Co., Ltd. / 173 figures, 4 figures Sq, +5 figures

Claims (4)

[Claims] (1) A commercial AC power source, a discharge lamp that emits ultraviolet rays, a discharge lamp lighting circuit that lights the discharge lamp using the commercial AC power source, an incandescent lamp for illumination, and a discharge lamp that uses the commercial AC power source to illuminate the discharge lamp. An incandescent lamp lighting circuit for lighting an incandescent lamp, and an ultraviolet flaw detection power supply device for detecting defects such as scratches on the sample by irradiating the sample with ultraviolet rays emitted by the discharge lamp, wherein the discharge lamp lighting circuit and the The incandescent lamp lighting circuit is a power supply device for ultraviolet flaw detection characterized by converting the commercial AC power into an AC power with a frequency higher than the commercial frequency and then supplying the AC power to the discharge lamp and the incandescent lamp. (2) The discharge lamp lighting circuit includes a rectifier circuit that rectifies the commercial AC power supply, a smoothing circuit that smoothes the pulsating waves rectified by the rectifier circuit, and a DC output of the smoothing circuit that converts into a high frequency wave. 2. A power supply device for ultraviolet flaw detection according to claim 1, characterized in that it is constituted by an inverter circuit. (3) The power supply device for ultraviolet flaw detection according to claim 2, wherein the inverter circuit is a push-pull type transistor inverter that performs self-oscillation and includes a resonant circuit. (4) The incandescent lamp lighting circuit uses direct current, which is the output of the smoothing circuit of the discharge lamp lighting circuit, as an input power source. A power supply device for ultraviolet flaw detection described in the above.